Refrigerating mechanism



Jan. 15, 1935. J R REPLQGLE 1,987,708

'REFRIGERATING MECHANISM Filed March 15, 1934 INVENTOR. J25 7?.Hep/051a.

A TTORNEYS.

Patented Jan. 15, 1935 PATENT OFFICE 1,987,708 V anrmemrnve MECHANISMJohn R. Replogle, Detroit, Mich, assignor to Copeland RefrigerationCorporation, a corporation of Michigan Application March 15, 1934,Serial No. 715,601

6 Claims. (Cl. 62-115) This invention relates to refrigerating mechanismand particularly to a construction in which means are provided fordampening out audible vibrations of certain vibratory parts thereof.

Objects of the invention include the-provision of means for dampeningthe vibratory movement of a part operatively connecting a vibratory 4element and a stationary element; the provision of an operative fluidconnection between a vibratory element and a fixed element capable ofpermitting substantially unrestricted vibration of the vibratoryelements but without itself vibrating at a rate which will be audibletothe human ear; and a fluid connecting device between a vibratorymember and a fixed member having a natural period of vibration sensibleto the human ear and having a weight associated therewith so constructedand arranged as to modify its natural period of vibration to such anextent that any vibrations set up therein are inaudible to the humanear.

Further objects include the provision of a refrigerating mechanismincluding a fixed condenser, a resiliently mounted compressor and atubeconnecting the discharge side of the compressor with the condenser, thetube having means associated therewith so constructed and arranged as tomodify the natural period of vibration of the tube to a rate ofvibration inaudible to the human ear;v to provide a refrigeratingmechanism including a base having a condenser fixed thereto and acompressor resiliently mounted thereon, the compressor being connectedto the condenser by means of a conduit having a natural rate ofvibrationaudible to the human ear, and theconduit having a weight amxed there-'to so modifyingits natural period of vibration as to render vibratorymovement of the conduit inaudible to the human ear.

The above being among the objects of the present invention, the sameconsists in certain novel features of construction and combinations ofparts to be hereinafter described with reference to the accompanyingdrawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which illustrates a suitable embodiment ofthe present invention throughout the several different views,

Figure l. is a side elevational view of a re-: frigerating unit.

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1. a

Fig. 3 is an enlarged sectional V ew of the conduit connecting theIcompressor and con= denser, taken on the line 3-3 of Fig. 1.

Certain types of refrigerating mechanisms include a refrigerating unithaving a base upon which a motor compressor unit and a condenser E aremounted so as to be. capable of being applied 1 to or removed from arefrigerator cabinet in uni tary condition. The motor compressor unitincludes rotating, and usually in addition reciprocating parts which,particularly when they are 10 driven at relatively high speed as inmodern constructions, are more or less subject to vibration due tovarious reasons. In order to prevent these vibrations from becomingnoticeably apparent in the refrigerator cabinet, it is the customaryprac= l5 itice to resiliently mount the motor compressor unit, as byfloating it on springs, so that the effects of its vibratory movementare minimized in the cabinet itself.

It is, of course, necessary to connect the dis- 2c charge side of thecompressor with the condenser and this is usually done through themedium of a copper tube of suflicient length to permit it to yield tothe vibratory movementsof the motor compressor during operation withoutmaterially 25 restricting the otherwise free movement of the motorcompressor and without endangering breakage of, the tube due to thevibration and bending which it is necessarily subjected to in connectingthe vibrating part to the fixed part. 30 I have found in many cases,however, because of the shape which the-connecting tube ,must as= sumein connecting the motor compressor with the condenser, caused by'thearrangement of these 'two parts as necessitated by requirements 35 ofspace or design, that the tube has a natural period of vibration withinthe audible range of the human ear, and because of -the fact that duringoperation of the refrigerating mechanism it is constantly subjected tothe vibratory move= ments of the motor compressor, it has a tendency toand actually does vibrate at its natural period. I have found that thevibration of the tube in this manner is often apparent as a low butaudi- 45 ble hum and its nature is such that it is often diflicult todetermine that it is actually the source of a hum. I have furtherfound'that it is pos and in which like numerals refer to like partssible to eliminate the audible effects of vibra tion of this connectiontube by changing its nat 50 ural period of vibration to one outside, andpreferablybelow, a rate of vibration audible to'the human ear. Thesimplest and most economical method for effecting this result is tosecure to the tube,'pre ferably at a point intermediate its 55 ends, aweight of. sufficient mass to effect desired result.

Referring now to the drawing, there is illustrated a refrigerating unitincluding a base or support indicated generally at 8 comprising a pairof spaced L-shaped angle iron members 10 which are secured together intheir spaced relation by means of a pair of spaced, opposed angle ironmembers 12 arranged in perpendicular relationship with respect to thefoot of the members 10 and fixed to the upper surface thereof as bywelding or other suitable means. Referring now to Fig. 1, a condenser 14is fixedly mounted upon the left hand end of the base. Upon the centralportion of the base: a motor compressor unit, indicated generally at 16,is mounted by means of three studs 18 fixed therein and projectingdownwardly through cooperating portions of the base 8 and about each ofwhich a coil spring 20 is positioned to resiliently support the weightof the motor compressor unit 16 upon the base. Nuts 22 are preferablyprovided on the studs 18 below the base 8 in order to prevent completedisengagement of the motor compressor unit16 from the base, particularlyduring shipment.

the

The motor compressor unit 16 includes a finned main portion 24 whichserves as a casing for a suitable electric motor (not shown) and anassociated portion 26 which includes a compressor mechanism (not shown)of anysuitable design operatively connected to the electric motor withinthe portion 24 and hermetically sealed with the motor within the casing.A bracket 28 is shown secured to the left hand end of the unit 16 inFig. 1 for the purpose of supporting a small electric motor 30 fordriving the fan 32 provided for causing a circulation of air through thecondenser 14. In the particular construction shown, the unit 16. andparticularly the compressor portion 26 thereof, is shown as beingprovided with a refrigerant discharge connection 34 which is connectedby means of a tube 36 with the inlet or upper end of the condenser 14.The tube 36, as indicated in Figs. 1 and 2, extends to the left, asviewed in Fig. 1, into the plane of the fan 32 and then, as indicated inFig. 2, is bent into a ring-like form encircling the periphery of thefan 32 in order to obtain proper length thereof, and then is again bentto the left to make connection with the condenser 14. Preferably, inorder to reduce the stress in the tube 36 due to the relative vibrationbetween opposite ends thereof, the main portion of the tube is flattenedas best indicated in the sectional view of Fig. 3.

From the above description it will be apparent that in the constructiondescribed and shown, the condenser 14 is fixedly mounted upon'the base 8and the motor compressor unit 16 is resiliently mounted thereon so as toenable it to vibrate relative to the base. The tube 36 being relativelylong because of its having been bent into a circle as described, will beof such flexibility, taken as a whole, as to offer no substantialrestriction to the otherwise free vibratory movement of the unit 16. Theend of the tube 36 connected to the unit 16 will, however, duringoperation of the mechanism, vibrate directly with the vibratory movementof the unit 16 and this will have the effect of vibrating the tube 36 asa whole and, under certain conditions at least, will set the tube 36vibrating at its natural period of vibration. When the natural period ofvibration of the tube 36 is within the audible range of the human car itis obvious an audible hum or sound will result.

As previously explained, I have found that if a weight of the requiredmass is aflixed to the tube 36 at the proper location the natural periodof vibration of the tube 36 will be modified and if the weight is of therequired mass the natural period of vibration of the combined tube andweight will be outside of the range audible to the human ear; Such aweight is indicated at 40 and may be constructed of any desired materialand secured in any suitable manner to the tube 36. It may convenientlybe formed of brass and soldered to the tube 36. While the particularposition of the weight 40 may vary considerably, it will be found mosteffective for a given weight if it is secured substantially midwaybetween the point of connection of the tube 36 with the unit 16 and withthe condenser 14. When such a weight is affixed to the tube 36 anyaudible vibrainvention, the scope of which is commensurate with theappended claims.

What is claimed is:

1. In combination, a vibratable device, a substantially non-vibratabledevice, a fluid connection between said devices, said connection havinga natural period of vibration within a range audible to the human ear,and a mass secured to said connection intermediate the ends thereofmodifying said natural period of vibration thereof to a frequencyoutside of the range of vibrations audible to the human ear.

2. In combination, a rigid base, a device fixed to said base, a devicesubject to vibrations during operation resiliently mounted on said baseso as to permit movement thereof independently of said base, a fluidconnection between said devices fixed at opposite ends thereto, and aweight secured to said connection between the ends thereof limiting thenatural period of vibration of said connection and weight to a rateoutside of that audible t the human ear. 3. In arefrigerating mechanism,in combination, a rigid base, a condenser fixed thereto, a compressordevice supported on said base for relative movement with respectthereto, a tube connecting said compressor device and condenser, and aweight so constructed and secured to said tube as to confine the naturalperiod of vibration of .the combined weight and tube to a range outsideof that audible to the human ear.

4. In a refrigerating mechanism, in combination, a rigid base, acondenser fixed thereto, a compressor device supported on said base forrelative movement with respect thereto, a tube connecting saidcompressor device and condenser,.

having a natural period of vibration within a range audible to the humanear, and a weight secured to said tube between the ends thereof of suchmass as to limit the natural period of vibration of the weight and tubeto a range beyond that audible to the human ear.

5. In a refrigerating mechanism, in combination, a rigid base, acondenser fixed thereto, a compressor device supported on said base forrelative movement with respect thereto, a tube including a loopedportion connecting said compressor device and condenser having a naturalperiod of vibration within a range audible to the human ear, and aweight secured to said tube between the ends thereof of such mass as tolimit the natural period of vibration of the weight and tube to a rangebeyond that audible to the human ear.

6. In a refrigerating mechanism, in combination, a rigid base, acondenser fixed thereto, a compressor device supported on said base forrelative movement with respect thereto, a tube including a loopedportion connecting said compressor device and condenser, and a weightfixed to said tube approximately midway between the ends thereof and ofsuch mass as to limit the natural period of vibration of the combinedtube and.

weight to a range outside of that audible to the human ear.

JOHN R. REPLOGLE.

